M802 SSB transmission problems

[alctel]

Hi there,

Apologies for this, I did a search but a lot of the info seemed to be in SSCA links that are no longer available.

I have a M802 with a AT140 tuner. I have the following two problems

1) My voice transmission is very weak. Winlink seems to work great and I can send and receive emails ok - but on voice I can hear people on nets fine, but they can't hear me - or they can hear me but I am very faint.

2) On higher frequencies (above 8Mhz) it knocks over my electronics. The panel lights flash and more importantly, it knocks my autopilot offline. It also crashes the connection to the pactor modem.

I will explain my setup in as much detail as possible here as I have limited internet and can't check often

- I have serial number 0108304. I did a manual check of the circuit board and it appears the manual clipping fix has been performed.

- I have the CS-M802 software and checked - voice compression (COMP) is on.

- Voltage remains above 13v even on full transmit (I have a LifePO4 bank)

- I have a 4 amp draw on standby (holding mic button and not saying anything), 10 amps talking normally and 21 amps whistling.

- The radio is powered direct from the batteries - the positive lead goes to a standalone circuit breaker (not on a panel) and from there to the radio. The negative goes to the shunt (which also has everything else electrical led to it) and then to the radio. I'm wondering if I should remove it from the shunt, as it may be contributing to my second issue (the stray EMI knocking out autopilot)

- The tuner is an AT140. It's fed from the radio by a co-ax. From the tuner, it uses a standard size AWG 12 wire (5 foot long) that goes to a length of coated lifeline that is hauled up by a halyard (the alternative backstay antenna).

- I have put on ferrites in a lot of places and also a line isolator on the main coax from radio to tuner.

- The ground was a KISS, but I've also tried running a size 8AWG cable to a bronze thru-hull. This seemed to give me marginally better connectivity to sailmail but didn't resolve either of my two issues.

Any ideas would be very welcome - I'm kind of running out of ideas!

Thanks for any and all help!

[atoll]

the go to guy is K4wja
there was a thread a few weeks ago describing similar problems with a new M802,something to do with the vhf antenna connection for the gmdss and a limiter on certain freq when transmitting on hf
link below to a sticky he created,suggest sending him a pm

http://www.cruisersforum.com/forums/...tc-198305.html

[AA3JY]

Tuner may not be tuning..try cleaning your connections..

[Auspicious]

Originally Posted by alctel

I have a M802 with a AT140 tuner. I have the following two problems

1) My voice transmission is very weak. Winlink seems to work great and I can send and receive emails ok - but on voice I can hear people on nets fine, but they can't hear me - or they can hear me but I am very faint.

2) On higher frequencies (above 8Mhz) it knocks over my electronics. The panel lights flash and more importantly, it knocks my autopilot offline. It also crashes the connection to the pactor modem.

I suggest you buy, borrow, or beg for a power/SWR meter. Your current draw numbers are very helpful.

If you switch the mode to FSK you'll get full power by just pressing the mic button. It would be helpful to measure output power and input current at the same time. This is more repeatable than whistling into the mic.

An alternative backstay antenna is just fine. How is your 12 AWG lead wire attached to the lifeline wire? Can you provide a picture? How close does it run to the backstay, bimini bows, and other metal? Is the rigging bonded? How long is the lifeline wire? I can think of a lot of unlikely reasons for a light signal - more information would help narrow things down.

Don't worry about the panel lights. Do you remember crystal radio kits? You could receive radio signals with what amounts to a metal whisker on a rock, usually galanium. An LED is a metal whisker on a rock, usually silicon. The flashing lights are the indication of detecting radio energy. Nothing wrong and nothing to hurt.

Autopilot interaction is common. The same thing is going on. The autopilot is in an unshielded plastic box packed full of switching transistors - more metal whiskers on rocks, but these are connected to other things and turn them on and off. First step would be ferrite beads on all the power and signal lines attached to the autopilot computer. If that doesn't work build a metal box around the autopilot and ground that.

Your install sounds good.

[Brian.D]

Along with Auspicious' comments, did this just start? Or has this been going on for awhile? New radio or new install? For the issue within the boat it sounds like common mode current run amok. Common mode currents are caused by a mismatch at the antenna, or tuner input. It is RF that is being sent back to the source. So I would agree that it sounds like the turner is not doing its job. An SWR meter would indicate high (>2:1) SWR. This can be fixed by adding at the tuner input a 1:1 Common Mode Choke. But it doesn't fix a faulty tuner. https://www.balundesigns.com/feedline-isolation-baluns/

As for the voice it sounds like your mic is on it's way out. If your data is getting through and your voice is not then a mic could be the problem. Can you barrow one or maybe order a new one. Doesn't hurt to have a spare anyway.

I also agree to do a PM (preventive maintenance) of the cables and connectors, and check your RF ground. Disconnect, reconnect to break up any gunk between contacts.

[Auspicious]

Originally Posted by Brian.D

For the issue within the boat it sounds like common mode current run amok. Common mode currents are caused by a mismatch at the antenna, or tuner input. It is RF that is being sent back to the source.

Yes - this can also happen when the lead wire connection to the antenna fails. Happens a lot when people use hose clamps as electrical connectors.

[alctel]

Thanks a lot for the suggestions.

It's been going on since I installed the radio, a few years ago - I think. Though I seem to remember that when I first installed the radio I could connect to other nets fairly easily? It's been quite a while though.

FSK mode shows 15amps on my clamp on meter (interestingly - my main amnmeter on the control panel that is linked to the main shunt shows half of what the clamp on shows when I do these tests - is that normal?)

The tuner seems to tune fine - I can hear it buzzing away and then stopping when I hit tune, or press the mic button.

I've attached a picture of the connection to the lifeline below (after I've peeled off the tape). It's about 2 - 3 inches away from the pulpit, rigging is not bonded. Around a foot from bottom of backstay



It seems I need to try to get hold of a SWR meter and a spare mic, both of which may be problematic as I am halfway up the sea of cortez. I'll ask on the morning net here, maybe I will luck out.

Thanks again for the responses.

[Brian.D]

There is evidence of corosion visible on parts of the connection. I would recommend that you disconnect the GTO15 wire and clean or replace the clamp. Also, the flat head looks like a hack job (not blaming you) and should be replaced with the appropriate bolt. Remove all that tape and use heat shrink (a little harder to move around the parts) or use self-amalgmating tape. Self-amalgamating tape will form fit itself around the connector keeping it water tight.

Honestly, I would remove that entire connector and make the GTO15 bare wire connect directly to the wire rope. This can be done by inserting the GTO15 bare wire into the same sleeve hole that the wire rope is using. Then crimp them together. Like this, but don't include the insulation of the wire rope.



Do you know anyone who can send you parts to your next point of arrival's post office? That might help. Early Christmas presents. LOL

[alctel]

I see - I will redo that connection. I have some gto15 I picked up a year ago that I've been meaning to swap in for the awg cable I've been using. Will report back with results

[Auspicious]

Originally Posted by alctel

Thanks a lot for the suggestions.

The connection of the lead wire to the antenna is suspect, at least in part because the ring terminal is not a good mechanical solution.

What I do is use a stainless steel fence wire clip. The GTO-15 and the antenna go through the clip, you put a blue crimp ring terminal on the end and fasten that to an end of the clip. This separates mechanical and electrical connection and makes inspection easy. I can send you pictures.

15 A at high power for an 802 is low, and odd compared to the 21 you report for whistling into the mic. If everything is properly calibrated you should see the same number on your panel and from your clamp-on. Can you confirm that the clamp-on is AC/DC and not just AC? Has anything ever been calibrated? I ship my gear back to Fluke every year for lab calibration and use that to calibrate panel meters for customers.

Part of the challenge is that most marine service companies don't calibrate their gear. You may want to find someone you can count on. Ham radio clubs are a good start - check with whoever maintains repeaters.

A power/SWR meter should be able to be scared up in an anchorage. Check the frequency coverage as that makes a difference.

I'd expect that SOMEONE in the sea of Cortez who has an 802 and will lend your their mic for a beer. Cruiser's VHF net?

I have some speculation that is centered on the lead line to antenna connection but I'd like more information. Note that the antenna starts at the tuner stud. If the connection has failed you have a five foot antenna. Not entirely consistent with good receive performance but possible.

You can write me at dave@auspiciousworks.com and we can schedule a phone call if you like. Do you have Skype or Whatsapp or something on your phone so we can share video and you can show me things?

[Cpt Pat]

I see only one mention of ferrites here, so I'll add to that.

Stray radio frequency interference (RFI) is normal in a new installation. When I first installed my 100 watt SSB:

1. My navigation lights flashed like a disco dance floor when I transmitted
2. My PC rebooted
3. My autopilot went berserk
4. My LED steaming (masthead) light burned out entirely
5. My bilge pumps cycled

I solved those problems with snap on ferrite suppressors. I've lost count of how many I used. Placement was by trial-and-error. Here's my source: https://www.dxengineering.com/search/part-type/ferrite/product-line/dx-engineering-ferrite?autoview=SKU&sortby=Default&sortorder=Asce nding

Now, if you didn't have stray RFI problems, and they have suddenly appeared, that's a different story. I'd do this. Listed in order of difficulty and likelihoods. Stop at any point if the problem resolves.

1. Clean and reseat all RF connections. Rust never sleeps.
2. Think back on what you did just before the problem started. Undo whatever that was. If that resolves the problem, rethink how you did that, then reconfigure.
3. Check the SWR (as suggested above) between your transmitter and your antenna tuner. After tuning the antenna, it should be something reasonable, like a 2 to 1 ratio (lower is better). If the test fails, don't blame the tuner until you've tested everything else first. The problem may just be beyond the extremes for which the tuner can compensate. High SWR between your radio and the tuner will cause that coax to behave like an antenna - spewing stray RFI and reducing the efficiency of your antenna.
4. Check the integrity of your RF ground at your antenna tuner. Disconnect, burnish, and reconnect all of the connections at the tuner output. RF grounding on a boat is a separate topic. I could write a book on that. If it worked before, I wouldn't try reconfiguring it except as a last resort. Just check the connections for now.
5. If you have an insulated backstay antenna, disconnect the coax or feedline connection (at the antenna or the tuner) and measure the conductivity between ground and the antenna. The resistance should be very high: at least 10,000 ohms. If not, you may have a shorted insulator. Clean any salt off first before you bother taking more drastic actions. Those insulators should be hosed off after every sail.
6. Check the continuity of the feedline/coax connection to the backstay. You can use an ohmmeter. These connections often fail from stress, vibration, and corrosion. A copper wire-to-steel backstay connection is an invitation to corrosion. Replace the coax/copper wire connection. Expect to replace it regularly in the future. Don't try covering that connection with anti-chafe tape (like I've often seen). It just entraps water and salt. If you use any tape, use rubber mastic tape and mold it to a watertight connection. I personally just hose it off regularly and accept that the connection will fail and the wire will have to be routinely replaced. I don't like tape on stainless wire: it deprives the stainless of oxygen and contributes to accelerated corrosion.
7. If you have a coax cable running to the backstay, verify the coax outer shield at the antenna end is actually connected to RF ground. The wire backstay on the chainplate side of the insulator is a good choice, provided the chainplate is connected to RF ground. If not, use flat braided stainless steel strap to bring it to the RF ground at the tuner or any nearer RF ground connection. Here's a source: http://www.ags.bz/. This requirement is often overlooked. If the coax isn't grounded at the antenna end, the entire length of the coax radiates as part of the antenna. Did you recently run a DC wire near that coax? Even when grounded, the coax isn't "seeing" 50 ohms at the antenna, and it will still consequently radiate to some extent. If you follow the advice to place the tuner as near as possible to the antenna, you can minimize the radiated power off the coax.

Good luck. RF is a bit of a black art.

Patrick
N8QH

[MJH]

Originally Posted by alctel

Hi there,

Apologies for this, I did a search but a lot of the info seemed to be in SSCA links that are no longer available.

I have a M802 with a AT140 tuner. I have the following two problems

1) My voice transmission is very weak. Winlink seems to work great and I can send and receive emails ok - but on voice I can hear people on nets fine, but they can't hear me - or they can hear me but I am very faint.

2) On higher frequencies (above 8Mhz) it knocks over my electronics. The panel lights flash and more importantly, it knocks my autopilot offline. It also crashes the connection to the pactor modem.

I will explain my setup in as much detail as possible here as I have limited internet and can't check often

- I have serial number 0108304. I did a manual check of the circuit board and it appears the manual clipping fix has been performed.

- I have the CS-M802 software and checked - voice compression (COMP) is on.

- Voltage remains above 13v even on full transmit (I have a LifePO4 bank)

- I have a 4 amp draw on standby (holding mic button and not saying anything), 10 amps talking normally and 21 amps whistling.

- The radio is powered direct from the batteries - the positive lead goes to a standalone circuit breaker (not on a panel) and from there to the radio. The negative goes to the shunt (which also has everything else electrical led to it) and then to the radio. I'm wondering if I should remove it from the shunt, as it may be contributing to my second issue (the stray EMI knocking out autopilot)

- The tuner is an AT140. It's fed from the radio by a co-ax. From the tuner, it uses a standard size AWG 12 wire (5 foot long) that goes to a length of coated lifeline that is hauled up by a halyard (the alternative backstay antenna).

- I have put on ferrites in a lot of places and also a line isolator on the main coax from radio to tuner.

- The ground was a KISS, but I've also tried running a size 8AWG cable to a bronze thru-hull. This seemed to give me marginally better connectivity to sailmail but didn't resolve either of my two issues.

Any ideas would be very welcome - I'm kind of running out of ideas!

Thanks for any and all help!

I agree with others that your GTO15 connection to the antenna could be better. I use a Split Bolt connector (cheap and available at Home Depot) to the backstay and run the wire with three inch rubber standoff spacers away from the backstay to the point of connection. Also, connect the GTO15 to the antenna with the wire looped pointing downward to avoid water entering between the copper wire and the plastic sheath wrapping.

FYI the KISS ground plane system works very well for me.

~ ~ _/) ~ ~ MJH

[Bycrick]

The fact that the relays in the tuner are "clicking" only means that the tuner is TRYING to tune. When it stops clicking, you may or may not be properly tuned. Check the TUNE indicator on the 802 display. When actively tuning, it will flash. When you have successfully tuned, the indicator remains on. If you don’t succeed, the TUNE indicator will disappear.

[Auspicious]

Some comments on the comments.

Originally Posted by Cpt Pat

Stray radio frequency interference (RFI) is normal in a new installation. When I first installed my 100 watt SSB:

1. My navigation lights flashed like a disco dance floor when I transmitted
2. My PC rebooted
3. My autopilot went berserk
4. My LED steaming (masthead) light burned out entirely
5. My bilge pumps cycled

Flashing nav lights (1) are either LED nav lights or a solid state switching panels both responding to the presence of RF. See my crystal radio description above. Rebooting PCs (2) also due to the presence of energy. See autopilot (3) description above. LED steaming light flashing (4) is not a surprise. I've not heard of one burning out completely. Bilge pumps with solid state level indicators commonly cycle (5).

RF gets into the devices one of three ways: through the power supply to the device, signal wires to and from the device, and direct impingement on the device. The first two can be addressed with ferrite beads; the last with shielding. Ferrite beads go at each end of the power and signal wires/cables. Shielding should be grounded. The only art is picking the most likely conduits for energy and tackling those first. The rest is science.

Originally Posted by Cpt Pat

5. If you have an insulated backstay antenna, disconnect the coax or feedline connection (at the antenna or the tuner) and measure the conductivity between ground and the antenna. The resistance should be very high: at least 10,000 ohms. If not, you may have a shorted insulator. Clean any salt off first before you bother taking more drastic actions. Those insulators should be hosed off after every sail.

The OP has an alternate backstay antenna.

The transmission line from tuner to antenna is NOT coax. The feed line is in fact part of the antenna. There are a lot of boats running around with five or ten foot long antennas--just the feed line--because the connection to the antenna has failed. The feed line is supposed to radiate.

Originally Posted by Bycrick

The fact that the relays in the tuner are "clicking" only means that the tuner is TRYING to tune. When it stops clicking, you may or may not be properly tuned. Check the TUNE indicator on the 802 display. When actively tuning, it will flash. When you have successfully tuned, the indicator remains on. If you don’t succeed, the TUNE indicator will disappear.

If tuning fails the 802 display will show THRU instead of TUNE.

[alctel]

The tuner displays tune, so I'm sure it's tuning correctly.

I redid the antenna connection with gto15 that I had and resealed it up. I also reattached the KISS as well as the cable to the thruhull so I have two grounds, but thinking this may be a mistake.

While doing that I noticed that the green earth wire that comes off the tuner control wire was connected at both the tuner and radio sides - apparently that's not a good thing?

I've already given the values I got with my clamp on ammeter, the one from the shunt shows 3 standby, 7 fsk/whistle and 5 talk (amp draw)

Not sure reason for discrepancy

I haven't had a chance to check yet with new antenna connection, the net this morning had issues.